1. Field of the Invention
The present invention relates to an optical-device switching apparatus of a microscope such as a revolver apparatus for switching objective lenses and a turret apparatus for switching mirror cubes.
2. Description of the Related Art
A revolver apparatus using a driving motor for switching objective lenses is described in Japanese Patent Application Laid-open No. H09-138354. The above revolver apparatus of a microscope includes a revolver body, a revolver rotator that is attached to the revolver body in a rotatable manner and includes a driving gear arranged near the periphery around a rotation axis, and a driving motor that rotates the revolver rotator using a power-transmission system. The driving motor is a step motor and controlled by a motor controller. A magnetic sensor probe, as a noncontact position detector, is fixed to the revolver body, and a position detection magnet is fixed to the revolver rotator. The number of the position-detection magnets corresponds to the number of lens-applied units. The position-detection magnet is fixed, keeping a fixed positional relation to the lens-applied unit that is formed on the revolver rotator.
In a rotor-plate switching apparatus of a microscope described in the above document, when a signal for positive rotation or negative rotation on of the revolver rotator is input to the motor controller, the motor controller outputs a driving pulse with a fixed frequency to rotate the driving motor at high speed so that the revolver rotator is rapidly rotated. Later, the frequency of the pulse is made low so that the driving motor is slowly rotated. During the low-speed rotation, the magnetic sensor probe detects the position-detection magnet, and then the revolver rotator stops rotating.